For many applications, it is essential for a turbine engine to start quickly and reliably. This is important, for instance, for turbine engine-driven missiles and similar applications wherein start times and start reliability must typically meet very stringent requirements. For such purposes, it has been common to utilize a starting turbine which is mechanically linked to the main turbine.
More specifically, the starting turbine is typically driven by rocket combustion by-products. Then, through the mechanical linkage between the starting turbine and the main turbine, the main turbine can more rapidly get up to speed than would be the case by simply utilizing the combustor that will produce hot gases for driving the main turbine thereafter. Unfortunately, this technique is known to be less than entirely desirable.
For instance, the utilization of a starting turbine greatly increases the overall cost and complexity of the operating components. It will also be appreciated that such a system is lacking in efficiency due to the necessity for indirect reaction of the main turbine to the starting turbine. Still further, the utilization of a starting turbine makes it difficult to provide for compact packaging of the operating components.
The present invention is directed to overcoming the above stated problems and accomplishing the resulting objects.